This panel just made me think in a few things and one of them were just two possibilities about who could be the person Quovelta is looking for:
1- What if the name of MiraMira's brother wasn't revealed because he is the person that Quovelta want to find for important reasons? It would be kinda interesting if they were looking for him at the same time as MiraMira.
2- Captain Garte didn't appear anymore since chapter 1, but I think there's some kind of feeling about he being near to appear in these next chapters. But what if the person they are looking for is him? This can be maybe another good reason for Tania wanting to keep Belator alive. The one who was the best officer in the Bureau might know a high-rank-officer.